Re: MTRR control

yuri mironoff (
Wed, 17 Dec 1997 13:21:40 -0500 (EST)


Great idea! However I'd like to plead the case of a system call
interface. (Not necessarily sysctl() - but maybe cachectl(), etc).

It would be very nice for humans to view MTRR settings through /proc -
but much easier (not to mention more standard) from a programming
interface to actually set them through a system call. Please let me

As time has proven again and again - /proc entry display format has
changed and all the software that depended on that display format became
instantly broken. There is a finite number of ways you can read/write
an integer into memory (as a system call argument) - there is an infinite
number of ways to display the same integer in a human-readable/writable
format. A properly designed system call would provide the most consistant
AND efficient interface.

Consider the inefficiency of /proc. I understant that setting MTRR
registers is done once in a blue moon - however its the principle that
counts. As it stands right now, far too many utilities/programs rely on
/proc. Look at "top": 2-8% CPU to display 70 mostly sleeping processes!
At the risk of repeating myself - an HPUX top manages to fit into 2%
with 400 processes - worse yet, on a slower CPU. Thats shameful - where
has the concent of efficiency gone?

As a final argument I'd like to present the possibility that not
everyone will enable /proc when running Linux.

Thank you for your time,


P.S. Sorry for the long-winded monologue but this is a pet pieve of mine. :)